Prior art other than that described above known to the present inventor, includes U.S. Pat. No. 3,234,512 granted to Burkhart Feb. 8, 1966, which discloses a plurality of light sources and receptors such that communication may be enabled by the appropriate interruption of the light sources.
U.S. Pat. No. 3,764,813 granted to Clement, et al., Oct. 9, 1973, discloses a coordinate detection system wherein a gridwork of intersecting light beams allows the user to determine the location of an object which interrupts the light source.
U.S. Pat. No. 3,775,560 granted to Ebeling et al, Nov. 27, 1973, discloses a crossed light beam positioned in an encoder which includes the provision for sequential scanning .
U.S. Pat. No. 3,955,562 granted Farrar, Jr., May 11, 1975, discloses an apparatus for measuring the range of motion which includes a plurality of mercury switches which are placed in pre-determined locations within the apparatus to be activated by motion of the wearer.
U.S. Pat. No. 4,198,623 granted to Misek et al, Apr. 15, 1980, discloses a touch-entry interactive cathode ray tube arrangement wherein the grid of infrared sources and detectors are non-parallel to more closely follow the curvature of the CRT face and minimize parallax errors.
U.S. Pat. No. 4,424,816 granted to Callahan et al, Jan. 10, 1984, discloses a neurological monitoring device utilizing electrodes placed on the scalp to record brain wave potential. The device includes a circuit for self-testing.
U.S. Pat. No. 4,444,205 granted to Jackson, Apr. 24, 1984, discloses a device including a flexible transducer for assessing joint mobility.
U.S. Pat. No. 4,692,739 granted to Dorn, Sept. 8, 1987, discloses a device utilizing light emitting diodes for input and display of data including a device for controlling sequencing.
U.S. Pat. No. 4,695,827 granted to Beining et al, Sept. 22, 1987, discloses a energy-interference signal for light-beam touch panels.
U.S. Pat. No. 4,703,316 granted to Sherbeck on Oct. 27, 1987, discloses a touch panel including two arrays of light detectors.
U.S. Pat. No. 4,761,637 granted to Lucas et al, Aug. 2, 1988, discloses an infrared touch input system.
U.S. Pat. No. 4,766,425 granted to Tallman et al, Aug. 23, 1988, discloses an oscilloscope capable of displaying a plurality of wave forms and a touch screen method permitting the operator to select a waveform.
U.S. Pat. No. 4,812,833 granted Shimauchi, Mar. 14, 1989, discloses a touch panel input device including an interruptible light beam.